Cementing apparatus for oil and gas wells



J. F. ROBINSON Er A1. 1,922,780

CEMENTING APPARATUS FOR OIL AND GAS WELLS Filed Nov. 11, 1932 i 2 sheets-sheet 1 Aug. 15', 1933.

Aug 15, 1933- J. F. ROBINSON ET AL CEMENTING APPARATUS FQR 011.:` AND GAS WELLS 2 Sheets-Sheet 2 Filed Nov. 1'1, 1952 3 wu um J. f.' Hob/)15011, l M. Clif/Co e Hummm@ Patented Aug. 15, 19153 UNITED STATES l CEMENTING APPARATUS FOR OIL AND GAS WELLS Jay French Robinson, Pittsburgh, Joseph M.

Chilcote, Wellsboro, and Wallace H. Haupt,

Tioga, Pa.

Application November 11, 1932 Serial No. 642,290

4 Claims.

This invention relates to new and useful im.- provements in cementing apparatus for oil and gas wells.

The primary object of the invention is to provide an exceedingly simple construction which may be manufactured at a very low cost and which will enable a person using the same to accurately determine at all times, during the cementing of an oil orgas well, just how the work is progressing.'

A further object of the invention is to provide cementing apparatus for oil and gas wells which will permit a well to be properly cemented with the minimum amount of vcement material being used and with the assurance that the said material will be properly positioned within the well hole.

Another object of the invention is to provide cementing apparatus for oil and gas wells which 20 will enable a well to be properly cemented with a minimum amount of material to be drilled after the cementing' job has been completed and the material set or hardened.

Still another object of the invention is to pro- Vvide apparatus for cementing oil and gas wells which includes specifically a particular cement forcing and oil and gas wells casing sealing plug with means for determining the accurate position of the plug during all stages of a cementing operation.

Other objects and advantages of the invention will be apparent during the course of the following description.

In the accompanying drawings forming apart of this specication and in which like numerals are employed to designate like parts throughout the same. 1

Figure 1 is a partly elevational view and partly vertical sectional view of the improved form of cementing plug embodying this invention positioned within the lower end portion of a well casing.

Figure 2 is a longitudinal sectional view of the improved form of cementing plug embodying this invention,

Figure 3 is a. plan view of a positioning d isc employed in connection with the plug.

Figure 4is a transverse sectional View of the disc shown inyFig. 3.V

Figure 5 is an end view of a guiding nose which forms a part of the lcementing plug,

Figure 6-is a plan view of one form of spacer wlhich is employed as a part ofthe cernenting l the axis of the nose 19 for a purpose-to be de- Figure 7 is a. plan view of a modiiled form of spacer, and, y

Figure 8,is a sectional view taken on line 8-8 of Fig. 7.'

In the'drawings, wherein for the purpose of 60 illustration is shown a preferred embodiment of this invention, the numeral 10 designates a casing shoe which is adapted to be positioned upon the lower end of a string of casing sections when the latter is lowered into an oil or gas well hole. This casing shoe is provided with a bore portion 11 which is of -greater diameter than the main bore 12 of the shoe. The difference in diameter of these two bore portions provides a shoulder 13. Adjacent this shoulder, the bore portion 11 70 is provided with a threaded section 14 adapted for connection with a threaded end portion of the next adjacent casing section 15.

In Figs. 3 and 4 there is disclosed a metal disc which may be formed of cast iron or other suitable material. This disc is of flat formation and includes the annular rim portion 16 which has attached thereto thethree-equi-spaced web portions 17 connected at their inner ends. This formation provides the three equi-spaced, sec- 'tor-shaped apertures 18. This disc will be termed a positioning disc or member and is adapted to engage the shoulder 13 formed in the bore of the casing shoe 10. This vpositioning disc is intended to be secured to the shoe 10 in any suit- 85 able manner, such as by brazing, welding or the like. It also may be held in position solely by being clamped between the shoulder 13 and the inner or lower end of the adjacent casing section 15. The positioning disc is intended to be arranged in the casing shoe in the manner illustrated in Fig; 1 when the string of 'basing sections is lowered into the well.

The cementing plug employed for forcing the charge of cement material downwardly through the well casing and outwardly of the lower end of the same is best illustrated in assembled views 'in Figs. 1 and 2. This cementing plug consists of a nose portion 19 which preferably is formed of wood and is provided with the cylindrical portion 20 and the tapered or frusto-conical end por- -tion 21. The periphery of this nose 19 is formed with a plurality of lonigtudinally extending, semi-circular grooves 22. These rgrooves extend the full length of the nose portion 19 and assist in the function of the nose to'properly guide the plug during its downward movement through y the well casing. The plug 19 is illustrated indetail in Fig. 5. A threaded bore. 23 is formed in a bailer.

scribed at a later point. It further will be noted that the opposite ends 24 and 25 of the nose are squared or occupy parallel planes which are normal to the axis of the nose.

Next adjacent the nose, and engaging the flat upper end surface 25 thereof is a leather disc 26. This disc assists in packing the plug within the bore of the well casing. The disc is formed with a central aperture 27 adapted to register with the bore 23 of the nose.

` Engaging this leather disc 26 is the web portion 28 of a leather packing cup 29 which is formed with a peripheral portion arranged at right angles to the web portion 28. A spacer member 30 is positioned within the peripheral portion ofthe leather packing cup and is adapted to space therefrom a second leather packing cup 31 which is formed in the same manner as the previous packing cup. Next adjacent this second packing cup 31 are two additional spacers 30. A third packing cup 32 is positioned in engagement with the uppermost of the pair of spacers 30. This third packing cup 32 is adapted to have positioned therein a cast iron plate or disc 33 which reinforces the central portion 28a of the packing cup 32 and clamps this cup against the uppermost spacing member 30. A connecting screw or bolt 34 is passed through apertures formed in all of the packing cup members, the spacing members and the disc 33, and is threaded into the bore 23 of the nose 19. This screw or bolt retains all of these various elements in their proper relativepositions.

Fig. 6 illustrates in detail the type of spacer member 30 shown in the assembled views, Figs. 1 and 2. This type of spacer is intended to be formed of wood. Figs. 7 and 8 disclose a modified form of spacer. This modication is adapted to be cast of iron and includes a cylindrical rim portion 35, a cylindrical hub portion 36, and a plurality of pairs of spokes 37 adapted to connect the rim and hub portions. This cast iron spacer may be substituted for any or all of the wooden spacers 30 shown in the assembled views of the cementing plug.

The method of utilizing the apparatus above described for the purpose of cementing oil and gas wells may be described as follows:

It is to be understood that the packing cups function to prevent cement from passing upwardly around the plug when the latter is employed for forcing cement downwardly through the casing and outwardly of the lower end of the same. These packing cups also function to prevent leakage of water, or the like, employed as a hydraulic ram to force the cement outwardly of the lower end of the casing when the water is forced against the cementing plug. These cups also function to clean the walls of the casing duringthe downward movement of the plug therethrough.

The casing, during the operation of cementing a well hole, is run into the hole in the usual manner and' lowered to within-approximately twenty feet of the bottom of the hole and sustained at that position. A cementitious material is then mixed to the proper consistency and dumped into the hole through the bore of the casing until the portion of the hole below the end of the casing is filled and the casing has therein a column of cement approximately twenty Afeet in length. The plug assembly is then placed in the casing and forced to the top of the cement by means of Sumcient water is then run into the casing and in engaging the top of the plug will force the same downwardly until it reaches the positioning disc which is resting upon the shoulder 13. The movement of the plug downwardly through the casing until it engages the positioning disc will force substantially all of the cement outwardly of the casing and into the cavity of the well hole below the casing and around the same. The water placed upon the plug and employed for forcing the same downwardly against the positioning disc to expel the cement from the lower end of the casing will possess a sufiicient weight to prevent upward movement of the plug and the casing is then lowered slowly until the casing shoe 10 has firmly seated itself on the bottom of the hole. This lowering of the casing with the immovable plug positioned therein will cause the cement positioned in the well-hole below the lower end of the casing to be moved upwardly in the hole around the casing. This nal positioning of the cement gives additional assurance that there will be plenty of cement between the casing and the wall of the well hole to make an eflicient cement seal.

The casing may be originally positioned within approximately twenty feet of the bottom of the well hole by running a'bailer through the casing until it engages the positioning disc resting upon the shoulder 13. By measuring the length of the cable attached to the bailer, the position of the casing may be accurately determined. A bailer also may be employed for determining the positioning of the cementing plug in engagement with the disc resting upon the shoulder 13 after water has been forced against theplug to move the same downwardly to expel the cement from the lower end of the casing.

It will be noted that the positioning disc is provided with a plurality of open-ings 18 and that the nose 17 of the plug is formed with a plurality of longitudinally extending peripheral grooves 22. The segmental openings 18 of the positioning 115 disc will permit cement to occupy the various grooves 22 of the plug nose when the plug bears against the positioning disc. These fingers or bars of cement will, when the cement has hardened, function to prevent rotation of the plug 120 with respect to he positioning disc and the well casing,

When the cement has suiiiciently set or hardened, the plug and positioning disc may be drilled and further operations in the well continued.

It is to be understood that the forms of this invention herewith shown and described are to be taken as preferred examples of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without'depart- 130 ing from the spirit of the invention or the scope of the subjoined claims.

Having thus described the invention, we claim:

1. In cementing apparatus4 for oil and gas wells, the combination with a well casing, of a. flat, 135 apertured disc adapted to be secured within the lower end portion of said casing, and a plug adapted to force cement out of the lower end of the casing when moved downwardly therethrough into engagement with the flat disc, said plug hav- 140 ing longitudinally extending rgrooves formed in its lower end portion.

2. In cementing apparatus for oil and gas wells, the combination with a well casing, o1' a flat disc having a plurality of sector shaped apertures 145 formed therein and adapted to be secured within the lower portion of the said casing, and a fabricated plug structure adapted to be positioned in the casing to force cement out of the lower end of the same when moved downwardly there- 150 through and having means extending longitudinally thereof to receive cement to hold the plug against rotation when the cement hardens.

4. In an oil or gas well cementing @a guiding nose portion having a cylindrical part and a tapered part, said cylindrical and tapered parts having longitudinally extending peripheral grooves formed therein to receive cement while in use, a plurality of packing members, and means extending axially of the plug for connecting the packing members to the guiding nose.

JAY FRENCH ROBINSON. JOSEPH M. cHILCo'rE. WALLACE H. HAUPT. 

